Medical instrument with flexible wrist mechanism

Abstract

A medical instrument includes a unitary wrist structure having: a first connector portion having a lower stop surface, a compact flexure integral with the first connector portion, and a second connector portion integral with the compact flexure with the second connector portion having an upper stop surface integral with the compact flexure below the lower stop surface and forming an angle with the lower stop surface.

1 . A medical instrument comprising:
 a unitary wrist structure having:
 a first connector portion having a lower stop surface, 
 a compact flexure integral with the first connector portion, and 
 a second connector portion integral with the compact flexure with the second connector portion having an upper stop surface integral with the compact flexure below the lower stop surface and forming an angle with the lower stop surface. 
   
     
     
         2 . The instrument as claimed in  claim 1  wherein the compact flexure is a flexible hinge. 
     
     
         3 . The instrument as claimed in  claim 1  wherein the upper stop surface is directly under and mirrors the lower stop surface. 
     
     
         4 . The instrument as claimed in  claim 1  wherein:
 the second connector portion includes an upper relief clearance between and integral with the upper stop surface and the compact flexure; and 
 the first connector portion includes a lower relief clearance between and integral with the lower stop surface and the compact flexure, and forming a radius of the lower relief clearance different than the radius of the compact flexure and the upper relief clearance. 
 
     
     
         5 . The instrument as claimed in  claim 1  wherein:
 the first connector portion has a lower relief clearance between and integral with the lower stop surface and the compact flexure; and 
 the second connector portion has an upper relief clearance between and integral with the upper stop surface and the compact flexure, and forming a portion of a circular cylinder with the compact flexure and the lower relief clearance. 
 
     
     
         6 . The instrument as claimed in  claim 1  wherein the compact flexure is characterized as having an S-bend component less than or equal to twice the shear component of a deflection. 
     
     
         7 . The instrument as claimed in  claim 1  wherein the unitary wrist structure further comprises:
 actuator holes on the first connector portion and the second connector portion, with the actuator holes going through the first connector portion and the second connector portion in directions parallel to a center line; and 
 actuating members connected to the first connector portion and positioned through the actuator holes on the second connector portion. 
 
     
     
         8 . The instrument as claimed in  claim 1  wherein the unitary wrist structure has a cylindrical shape. 
     
     
         9 . The instrument as claimed in  claim 1  wherein the unitary wrist structure further comprises a third connector portion flexibly integral with the second connector portion to flex at right angles to the first connector portion. 
     
     
         10 . The instrument as claimed in  claim 1  wherein:
 the unitary wrist structure includes a central channel extending along a center line of the unitary wrist structure; and 
 the unitary wrist structure further comprising:
 an actuating member positioned within the central channel. 
 
 
     
     
         11 . The instrument as claimed in  claim 1  further comprising:
 a jaw mechanism connected to the unitary wrist structure; and 
 a tube connected to the unitary wrist structure opposite the jaw mechanism. 
 
     
     
         12 . A medical instrument comprising:
 a unitary wrist structure having:
 a first connector portion having a first lower stop surface forming an angle above a horizontal plane, 
 a first compact flexure integral with the first connector portion, 
 a second connector portion integral with the first compact flexure opposite to and aligned with the first connector portion with the second connector portion having a first upper stop surface forming the angle below the horizontal plane directly below the first lower stop surface and having a second lower stop surface sloped up at the angle, 
 a second compact flexure integral with the second connector portion, 
 a third connector portion integral with the second compact flexure opposite to and aligned with the second connector portion and having a second upper stop surface sloped down at the angle directly below the second lower stop surface and having a third lower stop surface sloped up at the angle, 
 a third compact flexure integral with the third connector portion, 
 a fourth connector portion integral with the third compact flexure opposite to and aligned with the third connector portion and having a third upper stop surface sloped down at the angle directly below the third lower stop surface and having a fourth lower stop surface sloped up at the angle, 
 a fourth compact flexure integral with the fourth connector portion, and 
 a fifth connector portion integral with the fourth compact flexure opposite to and aligned with the fourth connector portion and having a fourth upper stop surface sloped down at the angle directly below the fourth lower stop surface. 
   
     
     
         13 . The instrument as claimed in  claim 11  wherein the first compact flexure, the second compact flexure, the third compact flexure, the fourth compact flexure, or a combination thereof include substantially zero friction from the compact flexures. 
     
     
         14 . The instrument as claimed in  claim 11  wherein the first compact flexure, the second compact flexure, the third compact flexure, and the fourth compact flexure have an ABBA arrangement with the first compact flexure parallel to the fourth compact flexure and the second compact flexure and the third compact flexure are both rotated at a right angle to the first compact flexure. 
     
     
         15 . The instrument as claimed in  claim 11  wherein the first compact flexure, the second compact flexure, the third compact flexure, the fourth compact flexure have an ABAB arrangement with each of the compact flexure rotated at a right angle to the compact flexure to which it is adjacent. 
     
     
         16 . The instrument as claimed in  claim 11  wherein the first connector portion, the second connector portion, the third connector portion, the fourth connector portion, the fifth connector portion, or a combination thereof have upper relief clearances and lower relief clearances each forming a radius different than the compact flexures. 
     
     
         17 . The instrument as claimed in  claim 11  wherein the first compact flexure, the second compact flexure, the third compact flexure, the fourth compact flexure, or a combination thereof are characterized as having an S-bend component less than or equal to twice the shear component of a deflection. 
     
     
         18 . The instrument as claimed in  claim 11  wherein the first connector portion, the second connector portion, the third connector portion, the fourth connector portion, the fifth connector portion, or a combination thereof have upper relief clearances and lower relief clearances with each compact flexure forming a portion of a cylinder having a circular or an elliptical cross-section. 
     
     
         19 . The instrument as claimed in  claim 11  wherein:
 the lower stop surfaces are integral with lower relief clearances; and 
 the upper stop surfaces are integral with the upper relief clearances. 
 
     
     
         20 . The instrument as claimed in  claim 11  further comprising actuating members separately coupling the first connector portion, the second connector portion, the third connector portion, the fourth connector portion, the fifth connector portion or a combination thereof with an actuator system for individually controlling the portions of the unitary wrist structure. 
     
     
         21 . The instrument as claimed in  claim 11  further comprising a jaw mechanism integral with the unitary wrist structure at a distal end. 
     
     
         22 . The instrument as claimed in  claim 11  wherein the unitary wrist structure is made of:
 a moldable plastic or metal; 
 a joinable plastic or metal capable of being joined with other plastics or metals by hot air, heat, or laser welding; or 
 a metal shapeable by electrical discharge machining.